The present disclosure relates generally to subscription notification services and, in particular, to methods, systems, and computer program products for optimizing query evaluation and processing in a subscription notification service.
Subscription notification services are implemented over a communications network, e.g., as a Web service by a service provider entity. Subscriptions facilitate ongoing information requests based upon a topic of interest to a subscriber. Notifications (also referred to as messages and alerts) inform the subscriber when the criteria specified the subscription has been met such as the change in state of a resource within a management system. A notification source system that produces the information and services the subscriptions typically uses query filters for determining when to generate a notification when the aforementioned action meets the criteria specified in the filter.
With the growing popularity of these subscription notification services, some notification source systems are turning to notification brokers for providing a portion of these services. In this model, the subscribing entity subscribes to the notification broker system which, in turn, subscribes to the notification source system. The subscriptions are created by the notification broker on behalf of the subscribers, and the notification source then services the subscriptions for the notification broker.
Oftentimes, subscription notification systems that involve processing large volumes of subscription requests can become inefficient in that numerous subscription queries presented to a notification source may be redundant; that is, multiple subscribers are requesting the same information, which can cause needless backlogs at the notification source. Processing large quantities of requests, including those that are redundant, can negatively impact the quality and response times regarding the subscription request processing and the resulting notifications.
What is needed, therefore, is a subscription notification service that eliminates, or substantially reduces, the redundancies in subscription requests, as well as optimizes the way in which they are processed at the time of an event or incident that needs to be evaluated against the criteria specified by one or more subscriptions.